 |
A
wind turbine is an enormous fan working in reverse. An
ordinary fan uses electricity to power a motor, which
turns the blades and makes a breeze blow. In a wind
turbine, on the other hand, air rushing past the
propellers makes them rotate, which causes a generator
to operate and electricity to be produced.
Wind systems achieve varying degrees of efficiency,
depending on where they’re installed. Obviously, someone
who lives on a plain is going to produce more
electricity from a wind turbine than someone living on
the leeward side of a mountain. However, wind systems
can be a viable alternative energy source, especially
since they offer the same benefits as a solar array at a
smaller cost. |
ROTATION
There
isn’t just one wind turbine design that sets the
industry standard. There are several turbine designs
that take distinctive approaches to capturing the wind’s
power, from the recognizable thin blade trio to the more
exotic-looking eggbeater. Despite variations in
construction, however, the main purpose of the
propellers’ design is to maximize the amount of captured
wind power while reducing the likelihood of damage from
extreme winds.
GEARS
|
Like
the cogs inside a watch, a system of gears inside the
turbine transfers the rotation of the propellers to a
wire inside a generator. When this conductive wire
begins to rotate, the generator uses electromagnetic
principles to create an electric current. (See
illustration)
|
 |
ELECTROMAGNETISM
 |
Just as the Earth has magnetic poles, so too do
electrons. Recall that opposite fields attract
each other and like fields repel each other.
When opposite fields come into close contact,
they produce a magnetic force that moves from
the southern pole to the northern pole. If we
could see the magnetic force of an electron, it
would look like a series of loops moving outward
from the south and then back inward to converge
at the northern pole.
|
FLOW
This
magnetism can be used to get electrons to move along the
rotating wire. The wire is placed in between the poles
of a larger magnet, which means it’s right in the middle
of the big magnet’s south-to-north force. (See
illustration) The big magnet’s poles pull and push on
the electron’s poles. The electron struggles to find
equilibrium with the big magnet, but since the wire is
causing the electron’s position to constantly change it
can’t achieve equilibrium, and the magnetic forces start
to push it out of its place. When enough electrons start
moving, they jostle with one another for space and push
down the wire, creating an electrical current. This
current can then be used to power a load.
CURRENT
CONVERSION
Homes
and businesses typically operate on alternating current,
in which electrons move back and forth on the wire, but
a wind turbine on its own will produce either direct
current or wild alternating current. Wild AC is
so-called because its strength is unpredictable; it
depends on how fast the wind is making the wire spin.
To make the electricity produced by a wind turbine
usable in the home and to make it eligible to be dumped
into the utility grid, people who use wind power need to
buy an inverter so that they can convert their
electricity into generic AC.
COST
EFFECTIVENESS
As
mentioned in the introduction, wind turbines offer the
same financial benefits as solar arrays at a smaller
cost. Solar panels work at about 30 cents per kilowatt
hour; wind systems can cost about 17 cents per kilowatt
hour on a small scale. Wind-produced electricity becomes
most attractive on a large scale, with wind farms able
to produce electricity at a rate of about four to six
cents per kilowatt hour.
VIABILITY
Wind
turbines may not be a practical energy alternative in an
urban setting. Neighborhood associations might protest
if giant turbines start going up in people’s backyards.
However, if the space is available and there’s nothing
around to block the wind, very few obstacles exist to
stop interested people from installing a wind turbine.
|
